I develop a simple application usiing VB.NET, VisualStudio 2008, that read input from a serial port
(from another device). I use the class SerialPort.
Using HyperTerminal I can see the input , it's fine. looks like :
S0P,A,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0 S0P,A,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
[Code]...
I have a simple WPF windows application trying to read a serial port with the System.IO.Ports.SerialPort. When I try to read the incoming data in the DataReceived event, I get an exception saying that I don't have access to the thread. How do I solve it?
I have this in the WPF window class:
Public WithEvents mSerialPort As New SerialPort()
Private Sub btnConnect_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles btnConnect.Click
With mSerialPort
[code]....
Is this class normally slow or maybe there is something in my process making it slow.I have to import 170,000 rows of data from a fixed length text file into a SQL table. It takes about 2 minutes in a DTS package on SQL server 2000. But we are migrating to a SQL 2008 server and since this code has several manual steps and does not manipulate the data I thought it would be easier to use the TextFieldParser object to handle reading in the data.
Here is the code:
CODE:
I have a .dll provided by a vendor and it requires me to pass a handle to the com port the device is represented as in order to access some other functions. Can I get the handle from the SerialPort object? The device I'm working with is a USB-UART converter chip with auxiliary I/O. I need to access the I/O which involves using a Visual C++ 6.0 .dll which is the one that requires the handle to the Com port.
View 2 RepliesAfter browsing the internet on how to read RDF Triples, the only things i came up with were user created libraries and so on. Some MSDN documentation on Microsoft's website confused me as well, as trying to import the Namespace shown was not possible. (Maybe it's possible just in C#? no idea).So how would someone read an RDF Triple using VB.NET? RDF is an XML format in which data is stored in triples: subject, predicate, object.
Example:
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">[code]....
I am having a little trouble with the serialport object in VB2008. I have a program that will send a command to the slave device however the program will not read the data from the slave device. I know my computer is communicating with the slave device because in hypertem it has no problem. For example I send the word "AT" and I should get back a response of "OK",
View 9 RepliesI use the vb .net serialport to receive data from my instrument every second
View 11 RepliesEvery 5 to 10 seconds I receive 5-12 bytes of data (confirmed w/Hyperterminal). I can open the com port(btn1), read bytes(btn3) until bytes to read = 0, but then i'm stuck; the data received event doesn't seem to respond. If I close the serial port(btn2), re-open i can read more data until bytes to read = 0 then stuck again. I tried several suggestions for threads and delegate and invoke but none worked. (WIndows XP, VB 2008)
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I want to use IO.ports.serialport to receive ASCII data from an instrument (A Luxmeter for those interested). So far, i've been unable to read any single byte from the instrument using the IO.ports.serialport.A terminal window shows the datastream just fine, and I've used MScommlib to read the data without problems. I just had other problems with the latter, so I thought I'd give this IO.ports.serialport a try.The code runs fine, no errors. It just doesn't receive anything.Bytestoread stays 0 forever.I distilled the code to it's bare essence. What am I missing? Is it something obvious, or did I completely misunderstand the whole concept? (Which is not unlikely..)I did check the obvious, of course: settings, baudrate, cable is connected, instrument is sending, etc.[code]
View 6 RepliesI am writing a small application to see what data I am sending and receiving to my COM port (for a small hardware project based on url..).The problem I want to activate a "Serialread" or "SerialWrite" procedure as soon as data is waiting in the receive or send buffer.I have some basic skills so before I start digging in I would like to get some advice. Can I use a addhandler (I have read something about this on the internet but have to clue how to use it) or something else? Is there a way to check if data is in the buffer ready to be read or write??
View 2 RepliesI have a program where I need to periodically save the data to a database (if the computer suddenly shutdown) and also send the same data to a serialport.Alla data that is going to be sent and saved resides in two classes.his needs to be done every 1/10s.What's the best way to manage this?
View 2 RepliesI have a USB device which creates a Virtual Serial Port on Windows. I am using VB.Net to write and read from the port. My device responds with specific sized set of bytes, but I am finding that SerialPort.Read(byte-array,offset,number-bytes) does not return the full number-bytes but it also does not timeout or generate an exception. Repeated calls return additional fragments (up to 3 calls required). Python code using pySerial does not have the same problem.So, what am I doing wrong here? Am I expecting too much?
Some scenarios are:I write a command to the port and expect to get 4 bytes in response. I get 1 byte first and then 3 bytes on the subsequent call.I write a command and expect 21120 bytes in response. I get 1, 12671 and then 8448 bytes in 3 calls to read from the port.
Here are some excerpts from my code:
Private Sub SetupVirtualSerialPort()
Dim portName As String = "COM" + (m_DeviceContext * -1).ToString
Const baud As Int32 = 9600 '7680000
Const parity As Parity = parity.None
[code]....
I'm trying to make a simple Class that reads data from a SerialPort.The Device returns a number of lines of Strings.[code]However running this code in a Form with one TextBox Control (txtLog) Allways results in the "The operation has timed-out." Exception.[code]
View 3 RepliesI am writing a serial application using VB .net Framework V4 , where I use a background worker to Read a file and send it to a serial port using SerialPort1.writeLine method. The BackgroundWorker1.ProgressChanged Event handler sub Updates the Line Number to a TextLabel and adds each line sent to a RichTextBox using RichTextBox1.AppendText() method on main form (Form1).
The problem arises at 115200 Bauds (and higher),may be because now the text is updated real fast on the form an unhandled Exception in BackgroundWorker1.ProgressChanged Event handler sub occurs. Otherwise at lower baudrates ex: 9600,19200 etc. Application Runs Perfectly Fine.
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i want to receive data to my pc from external hardware but i don't know how to do it since i am new to vb.net. the code in vb.net to receive data using serial port rs232.
View 1 Replieshow to recive data from serialport & send it to anthor pc running my program & resend to the same serialport on the other pc?
View 4 RepliesRecently we have connected one bluetooth device which receive data from our serial device. The bluetooth device further transmite this data to a Windows Mobile which is bluetooth enable. Baud rate of whole system is 19200 with 7 data bit and 1 stop bit.When we send command to serial device through bluetooth device it is accepting the command and respond accordingly. but some of data byte of string is desplay as question mark (?).But in case we connect the serial device directly to PC, the string received is correct.[code]Response given by Serial Port is "?09?D03?A D?
View 1 RepliesRecently we have connected one bluetooth device which receive data from our serial device. The bluetooth device further transmite this data to a Windows Mobile which is bluetooth enable. Baud rate of whole system is 19200 with 7 data bit and 1 stop bit.When we send command to serial device through bluetooth device it is accepting the command and respond accordingly. but some of data byte of string is desplay as question mark (?).[code]...
View 4 RepliesI am writing a small app that is retrieving data from a device connected to a virtual com-port. I connect without problems to the device using the settings 9600-8-N-1.
I need to send the command <esc>MS , the device then sends back the data to a computer. I have tried this using Hyperterminal with success. I also did this with Excel and VBA. I used the MSComm32 Active X control:
MSComm1.Output = Chr$(27) + "M" + "S" + Chr$(13)
Msgbox(MSComm1.Input)
This made the data from the device pop up in a messagebox. I am writing a winforms app in vb.net, using VS2005. I have a form, on which I have a Placed a SerialPort control, named sp. My sample code is as follows:
Private Sub Form1_Load(ByVal
sender As System.Object,
ByVal e
[CODE]...
This returns the error message "Error: expecting a command". I have done som tests in HyperTerminal, and have concluded with:
-If I dont send <esc>, I get error "Expecting a command"
-If I send wrong command (ie MD instead of MS) i get error "Bad command"
Based on this, I suspect that I don't pass the escape character correctly to my device. So I wonder how to do this?
read data from a text file with SERIALPORT while using "StringReader.ReadLine"?
View 8 RepliesI'm trying to get the price out (90.0) of this xml document but get it to work, i've tried using the xmlTextReader and the ReadElementString function but I guess I need to get the attribute. I then looked at using the GetAttribute function.
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I have a program that will download files from a company website given a list of links. The site requires authentication, and I do have code that will set the authentication cookie in the request header. I get the authentication cookie from a Perl script we have. What I would love to do is have my vb .net program get the authentication cookie based on my username and password. The perl script goes to the following link:
[URL]
The it reads the cookie out of the response. Here is the code I have, but my cookie count always comes back at zero. :(
Dim cookieJar As New Net.CookieContainer()
Dim cookie As New Net.Cookie
Dim req As Net.HttpWebRequest
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I'm trying to pass a business object from one WinForm to another WinForm for modification, and then repopulate the text boxes, etc. on the first form with the updated values.However, it seems that the object values set in the second form are not "sticking" when the code control returns to the first form.Is there a way to view the memory location of an object in VB.NET? I want to first make sure that the object variable on the second form is pointing to the same memory address as the object on the first form. Then I can take it from there.
In a separate VB project, I passed a simple object to a second form, modified the values, and re-displayed the object's values on the first form. It worked fine. In my real app, I'm passing an object that is a property of another object, which may be why it isn't working.SOLUTION: The problem was that I was using a DeepCopy() function that I found to simplify copying the properties of one object to another. Removing that function and manually setting the values to the passed object on the second form (ex. obj.property1
I have published xml document through web service like this
<WebMethod()> _
Public Function HelloWorld() As XmlDocument
Dim xmlDoc As New XmlDocument
[code]....
I am creating some reports using object datasources.in my software the user can create a list of products specifying a code, the product name, the price and the vat rate (this last two attributes will be used as suggestions when the user will place the product inside an order).When a user creates an order he can place products within it by specifying for each product the quantity and he can also override the suggested price and the vat rate.So basically i have two models to represent the products:
ProductModel (used to define product name, product code and the default suggestion for price and vat rate)OrderProductModel (used to place products within an order, specify the quantity and override the default product suggestion for price and vat number)
ProductModel:
id
code
name
[code]...
(suppose orderProduct is an instance of OrderProductModel)Now the question is "how to define the report rule to access to code and name?"...I am using visual studio 2010 and by reading here:[URL]they says that the syntax: =Fields!Object.Value.attribute no longer works...
I'm having problems with an Invalid Cast Exception when I try and read a PDF from a database as a BLOB. I am able to write the files into the database no problems at all,however, when I try to retrieve them I just get InvalidCastException.Here is the code I'm using:
Protected Sub btnPDF_Click(sender As Object, e As EventArgs) Handles btnPDF.Click
' Request.QueryString["docid"].ToString();
Dim docuid As String = "b39a443d-ccfd-47f4-b333-f12cd94683d6"
[code].....
I have a variable defined as Object(,) that was read in from excel. Without getting into a for/next, is there a simple way to read the c-th column or r-th rown from that array into a single variable?
View 2 RepliesI have some data that is contained in HTML tables within a webpage. I need the simplest means of extracting the data for storeage in SQL tables. I am knowledgeable of how to add the data to SQL tables...this portion of the code is already written. I would like to pull the data into the VB.NET 2008 environment using the XML DOM or a more efficient option.
View 1 RepliesI'm trying to set the format of a column in a datagridview.When I put the format statement in the on load event for the form, it has no effect. When I put it in the cellformatting event I get the "Object reference not set to an instance of an object" error. I checked the column name. What I am doing wrong?
This is the code:Private Sub MeetingTblDataGridView_CellFormatting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) Handles MeetingTblDataGridView.CellFormatting
Me.MeetingTblDataGridView.Columns("Starttime").DefaultCellStyle.Format = "HH:mm:ss"
End Sub What I'm trying to do is get rid of the date part of a Date/Time field (stored in an Access database) in a datagridview column.
dp.SyntaxHighlighter.ClipboardSwf = '/dp.SyntaxHighlighter/Scripts/clipboard.swf'
dp.SyntaxHighlighter.HighlightAll('09dde30f062e451a854266e66205b1cf')
I was create Access database with Access 2003. I create VB project with Visual Studio 2005 Standard With connection wizzard I create coonect with this Access database, select all tablesI see this database inside Data sources and inside Server explorer Test connection is OK When I drag and drop table from Data sources, Wizzard don't create DataGridView, DataSourceBinding etc .. and I see popup window with mesage: Object reference not set to an instance of an object and then "game over"
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